/*
 * Copyright (c) 2012 Johan Fylling
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy 
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights 
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
 * copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
 * THE SOFTWARE.
 */

part of engine;


abstract class ParticleSystem extends DynamicBody {
  final List<Particle>   _particles;
  final List<Constraint> _constraints;
  
  ParticleSystem () : this._particles = new List<Particle>(),
                      this._constraints = new List<Constraint>() {
    
  }
  
  /**
   * Factory Constructor that creates a Particle System that aproximates the given Collidable.
   * Collidables of unknown type will not create a Particle System; instead null is returned.
   */
  factory ParticleSystem.fromCollidable (Collidable collidable, num mass, [Vector2 position, num angle=0.0]) {
    ParticleSystem ps = null;
    
    if (collidable is CollidableCircle) {
      ps = new PointParticleSystem(mass, position, angle);
      ps.collidable = collidable;
    } else if (collidable is CollidableRectangle) {
      ps = new RectangleParticleSystem(mass, (collidable as CollidableRectangle).halfSize, position, angle);
      ps.collidable = collidable;
    }
    
    return ps;
  }
  
  Collection<Particle> get particles => this._particles;
  
  void getParticles (List<Particle> list) {
    list.addAll(this._particles);
  }
  
  void addParticle (Particle p) {
    this._particles.add(p);
  }
  
  Collection<Constraint> get constraints => this._constraints;
  
  void getConstraints (List<Constraint> list) {
    list.addAll(this._constraints);
  }
  
  void addConstraint (Constraint c) {
    this._constraints.add(c);
  }
  
  toJson () {
    var data = super.toJson();
    assert(data is Map);
    data["type"] = "particle_system";
    return data;
  }
}


class ParticleSystemStorageHandler extends DynamicBodyStorageHandler {
  call (StorageManager manager, Map attributes) {
    var mass = attributes["mass"];
    assert(mass is num);
    
    var collidableAttributes = attributes["collidable"];
    assert(collidableAttributes is Map);
    var collidable = manager.load(collidableAttributes);
    assert(collidable is Collidable);
    
    ParticleSystem body = new ParticleSystem.fromCollidable(collidable, mass);
    setAttributes(manager, attributes, body);
    return body;
  }
}
